The invention relates to a vehicle and more specifically to an aero marine vehicle designed to either travel upon the water or in the air.
In the past airplanes have had pontoons attached to them so that the airplane could land or takeoff from the water. U.S. Pat. No. 1,693,773 of Anderson discloses a pontoon for an airplane that has a stepped rear portion. U.S. Pat. No. 1,817,047 to Wallraff discloses an airplane pontoon having longitudinal air ducts on the bottom surface of the pontoon members and these air ducts have small holes through which exhaust passes from the airplane's engine may be forced to form a boundary layer of air between the pontoon and the surface of the water. The White et al U.S. Pat. No. 2,062,384 also shows for a seaplane that utilize exhaust gases from the aircraft's engine. The structures of these patents have not been entirely satisfactory as witnessed by the fact that none of these structures are presently being manufactured and being used.
The aero marine vehicle is a culmination of innovations and new technology that has come tegether through many years of study in the fields of hydrodynamics, aerodynamics, and mechanical engineering. Applicant's combination of simplicity and practicality are what make it so unique.
In the design work, certain rules have been followed because of the particular approach to the subject. That is, if one is designing a boat, it follows certain rules in hydrodynamics. If the design is for an aircraft, aerodynamics is followed. In the world of design, the designer is not allowed to cross over or so it seems. If he does, it leads to very expensive, complicated systems, (i.e. hydro-foils, hovercraft, etc). For these systems come a great deal of technology, but this technology has failed to do one thing. it has failed to fill the void of speed that exists on the water between 40 and 80 miles an hour.
In this category, the first units that come to mind are the cigarette boat or ocean-going racers. These units are still subjected to gravity, however. We then come back to the saveer pounding that takes place. In order for these hulls to take this type of punishment, they must be designed and built very strongly. Thus, additional weight is required. The more weight, the more power, the more fuel usage, thus a vicious cycle exists.
To maintain the higher speeds, these units have to use a large percentage of their installed horsepower, resulting in high fuel consumption, approximately one gallon of fuel per minute, resulting in a range of two hundred miles. This is really not very practical.
It is difficult to find an overall comparison for this speed range (40 to 80 mils per hour) as very few exist. One must assume that after 80 miles per hour, aircraft take over.
The most significant breakthrough in hydrodynamics in many years is the unqiue design of the aero marine vehicle's hulls. To eliminate suck-down or a large portion of the drag, applicant's hulls have been equiped with a turbocharged plenum chamber. This has been achieved by utilizing the wasted energy of the engine, the exhaust. The exhaust from one side of a V-8 engine powers a 20 psi turbocharger. The high pressure air of the turbocharger is fed by way of a by pass tube to the exhausting gases of the exhaust. This in turn eliminates the exhaust backpressure of the engines created by the turbocharger. This in turn pressurizes the plenum chamber, which is equiped with several exhaust ports. This creates a very significant boundary layer of air around the hull, thus eliminating a great deal of the hydrodynamic drag.
As the fresh air from the turbo re-enters the exhaust path, the combination of cool and hot gases are further cooled by means of an exhaust eradicator. The cooler exhaust gases being more dense then create a more solid boundary layer of air around the hulls. Since all of the exhaust gases are fed to the plenum chamber, the chamber now becomes a silenser or large muffler. Thus the annoying exhaust noise is all but eliminated.
In selection of the hull design applicant again returned to the basics. In water tunnel tests, it has been proven that the flat plane or the ski is the lowest drag profile of all of the planing devices. Thus applicant has used a flat plane for the bottom surface of his hulls. A V-hull is mostly designed for high impact loads or for comfort. The end result is more drag because of the amount of wetted surface.
Preferably applicant would have his hull constructed of aluminum with a high impact polymer surface.
The final phase of hull selection is to try to achieve a high aspect ratio. Under normal circumstances, the first thing that surfaces when aspect ratio is pursued is stability. By placing the hulls on struts under the wings at a predetermined span, a great deal of stability is provided.
An example of some of the relationships developed for an aero marine vehicle using applicant's novel design, for a vehicle having a gross weight of 10,000 pounds would be as follows. The hulls would be approximately 38 feet long by 3 feet wide by 12 inches deep. Static (or at anchor) the vehicle, would displace only approximately 8 inches of water.
The aero marine vehicle has two modes, one being water-borne and one being airborne.
With applicant's novel aero marine vehicle, additional liberties over conventional marine craft is possible. For instance, conventional marine craft have under the waterline, shafts, logs, screws, rudders, and through-hull fittings just to name a few. Applicant's aero marine vehicle has one of these. In shallow water, conventional marine vehicles are subject to such things as sand picked by the screw. This in turn is picked by the water pump intake. The end result is damage to the water pump impeller. Any contact with the bottom by the screw normally results in some kind of damage, whether it be to the screw shaft, log, etc.
A propeller in the water works like a vacuum cleaner. It pulls in floating anchor lines, fishing lines, ropes, gill nets, and anything else that is close by. Because high pressure air is discharged through the hulls of applicant's aero marine vehicle, this air actually pushes objects away. It is possible to go over sand bars, weeds, gill nets, and even kelp beds, without damaging the objects or the hulls.
In different parts of the world, there is shallow water, whether it be the shallow bottom of a river, shallow reefs along the coast, or even the kelp beds along the coastline. These areas are closed to any kind of navigation as it now exists. Applicant's novel aero marine vehicle can now open up these areas safely, whether it be by patrol craft, passenger or even cargo aero marine vehicles.
The use of long narrow hulls on the aero marine vehicle give it a long reaching effect in light to moderate seas. The hulls are designed with "wave splitters". Wave splitters reduce the wave impact on the leading edge of the hulls. At lower speeds, they knife their way through the waves at the front of the attach point where the strut attaches to the hull.
A high speed planning hull, regardless of its design, weight or construction, is subjected to sever pounding in moderate or rough seas.
In designing the hulls, a great attention has been directed to impact loads that they would receive. Short or high density loads usally occur at lower velocities. These are usually present when encounters some type of surface disturbances, whether it be wind, or other boats, etc. This pounding effect usually occurs between the speed ranges of 20 to 40 mph, depending upon the size of the boat.
By having two hulls, there is a distribution of the load. Applicant's hulls have been spaced at such a distance that one hull does not know what the other hull is doing. In taking this approach, the hulls have to be spaced so as not to cause water impingement. That is, one hull creating a wake strong enough to impinge on the other.
A second approach that was taken in the design of applicant's novel vehicle was to put a hydraulic cylinder at the forward attach point of the hull to his struts. From the upper and lower sections of the cylinder, the piston being centered, there have been two hydraulic accumulators connected. When the shock loads are transmitted from the water to the hull, the hull in turn transmitts it to the ram and the ram transmitts it to the accumulators. Thus, the shock loads are greatly reduced. By reducing the shock loads at the entry point, it does two things. One, it provides a smoother ride, and two it will not allow these destructive loads to be transmitted to the main structure, thus reducing metal fatigue.
The hydraulic cylinder also performs another function. Since the hulls that have no steps, to allow for a rotation, by using the hydraulic cylinder the angle of attack can be controlled up to 10 degrees for liftoff or down a negative angle of attack for stopping. This functions as a trim device.
As the aero marine vehicle approaches high forward velocities, there are two things that occur simultaneously, ground effect and wing lift. The struts play a very important role in ground effect. The upper attach point is attached to the front and rear spars of the wing structure. The angle of the struts from the upper wing to the hulls is approximately 25 degrees. The overall distance of the wing to the water surface would be approximately 8 feet. The struts are a true air foil configuration. They are oriented outboard 3 degrees, or given a positive angle of attack. The three degree angle of the struts does not give additional lift as a wing because of the angle but it does perform two basic functions. First the struts form a tunnel, for a ram air effect. Secondly by using the true air foil configuration, it gives the vehicle a low drag profile. In the upper portion of the tunnel or at the underside of the trailing edge of the wing, over a distance of approximately 16 inches, this section is turned downwardly approximately 6 inches to form a downward curve. This downward curve does not apply to the outer wing angle.
In operation as the aero marine vehicle enters the realm of speed between 40 and 80 miles per hour, several things occur. The underside of the hulls are discharging high pressure air for an air cushion, ground effect is pushing from the bottom, the wing is lifting from the top, and a very significant amount of dampening is present from the wing. The forward rams in the hulls are further reducing shock loads. The use of the two hulls splits the distribution of the load and the long length of the hulls aids in stability.
In one of the alternative embodiments of the hull configuration, the exhaust ports formed in the bottom wall of the plenum chamber are directed downwardly and rearwardly at various degrees. If the exhaust port holes are 1/8 inch in diameter, the exhaust port holes make an angle of 50 degrees with respect to the bottom surface of the plenum chamber. If the exhaust port holes are 1/16 inch in diameter the exhaust port holes make a 55 degree angle with respect to the bottom surface of the plenum chamber. Additionaly, the exhaust port holes have a specific pattern in the manner in which they are arranged along the longitudinal axis of the bottom surface of the plenum chamber. Starting from a point centrally located between the lateral sides of the hull, exhaust ports 1/8 inch in diameter are aligned on imaginary lines making a 45 degree angle to the lateral sides of the hull. This pattern for the 1/8 inch exhaust ports is repeated along the length of the hull. Interspaced between the 1/8 inch exhaust ports are the 1/16 inch exhaust ports and they are also located on imaginary 45 degree angles. However the 1/16 inch exhaust ports are positioned on different longitudinal axes from those of the 1/8 inch exhaust ports in a staggered fashion. This allows waves created by the 1/8 inch exhaust ports to interact with the waves created by the 1/16 inch exhaust ports. Also the exhaust gases will be exiting the 1/16 inch exhaust ports at a faster speed and also at a different angle. All of these strucutres interact to provide a superior cushion of air between the bottom surface of the hulls and the top surface of the water. The spacing of these exhaust ports from each other and the number and size of the individual exhaust ports relates to the aero marine vehicle to be supported upon the water. Extending downwardly from the opposite lateral sides of the plenum chamber are rails that form a full displacement chamber therebetween. The crosssection of this full displacement chamber increases in size from fore to aft. For instance the height of the rails at the forward end of the plenum chamber might be 3 inches and the same rail at the rearward end of the plenum chamber might be 12 inches. This difference in rail height from front to rear is important since it provides a necessary angle of incidence that produces a positive angle of attack for the wings of the aero marine vehicle. This gives the plane a positive displacement on the waters surface.
The total diameter of all of the exhaust port holes in the bottom surface of the plenum chamber is set to relieve substantially all back pressure on the engine. Thus this total would vary with different sized engines. The total diameter of the exhaust apertures in the bottom of the plenum chamber is 2.5 inches per 100 cubic inches of engine displacement. For example, a 450 cubic inch engine would require at least a total of 11.25 inches of diameter for all of the exhaust ports. Therefore 60 exhaust ports of 0.062 inches in diameter give a total of diameter of 3.72 inches and 60 exhaust ports of 0.125 diameter give a total of diameters of 7.5 inches and when added together equal 11.22 inches of diameter which is substantially the amount required for the 450 cubic inch engine discussed above.
The length and width of the hulls is governed by hull pressure resulting from the gross weight of the vehicle. The acceptable hull pressure would be between the range of 3 ounces per square inch to 3 lbs. per square inch.
The angle that the bottom surface of the plenum chamber makes with respect to horizontal in between 1 degree 30 minutes and 4 degrees.